Reciprocating drive for straight knitting machines



Au 19, 1941. F. Mack 2,253,439

RECIPROCATING DRIVE FOR STRAIGHT KN I'I'TING MACHINES Filed July 29, 1959 2 Sheets-Sheet l Aug. 19, 1941. MacKAY 2, 53,439

RECIPROCATING DRIVEVFOR STRAIGHT KNITTING MACHINES Filed July 29, 1939 2 Sheets-Sheet 2 I n V nt'or. .Fhmc 1's [Yale/( a Patented Aug. 19, 1941 UNITED STATES PATENT OFFICE RECIPROCATING DRIVE FOR STRAIGHT KNITTING MACHINES Francis MacKay, Port Dover, Ontario, Canada Application July 29, 1939, Serial No. 287,344

'7 Claims.

The principal objects of this invention are to provide a simple but eificient form of lost-motion or relief drive which will operate with precision and which will obviate the necessity of providing the usual friction box drive on straight or fullfashioned knitting machines and which will eliminate the difficulties associated with this now widely used form of friction drive.

A further and important object is to ensure more uniform loop formations at the selvedge edges of the knit fabric and to provide a simple but accurate form of adjustment for this purpose by means of which the selvedge formation in one knitting zone may be controlled relative to those of the remaining knitting zones and ensure the production of a more uniform and higher quality product.

A still further and important object is to provide a form of relief drive device which may be quickly interchanged with a standard operating member of the Coulier. drive to provide a motion relief drive connection with the so-called friction rod.

The principal features of the invention reside in the novel construction and arrangement of the drive connection between the Coulier motion device and the friction rod or other members of the machine to be reciprocated, whereby the excess motion of the primary drive over the variable movement of the thread carrier will be absorbed under conditions which will minimize the expenditure of power and which will also eliminate the heretofore unreliable and destructive action of the relative high speed frictional displacement of the friction box and friction rod and thereby overcoming the necessity of providing special cooling means for such rod.

A further and important feature resides in the novel provision of adjustable stop members which may directly co-operate with a stop member carried by the so-called friction rod and which are under the control of the narrowing head mechanism, and in the further provision of a micrometer form of adjustment between the reciprocated rod and selected carrier rod which control the displacement of the thread carrier.

In the drawing Figure 1 is a rear elevational view of an end portion of a typical straight knitting machine showing the present invention incorporated in the Coulier drive mechanism with the latter in the mid-position of its stroke.

Figure 2 is a somewhat diagrammatic struc tural view showing the displacement of the relief drive member of the present invention at the ends of the left and right oscillating strokes as indicated in dotted and full lines respectively.

Figure 3 is a fragmentary plan view showing the usual friction and carrier rods but with the friction box rigidly secured to the friction rod.

Figure 4 is an enlarged transverse section taken on the line 44 of Figure'l and broken away in part.

Figure 5 is a perspective detail of a drive connection constructed in accordance with the preferred form of the present invention.

, Figure 6 is a view similar to Figure 5 on a reduced scale illustrating a modified form of resilient compression means.

Figure 7 is an enlarged fragmentary elevational view of one end, of a knitting machine showing an improved form of adjustable narrowing stops co-operatively associated with the narrowing head mechanism. In the operation of straight or full-fashioned knitting machines it is customary to provide a friction box drive between the carrier rods and the friction rod on which the friction box was mounted for frictional sliding displacement, such rod being uniformly reciprocated by the usual Coulier mechanism.

The details of operation of such a machine are well known to those skilled in the art and it has been found in practice that the continual slippage of the friction box on the rod particularly during the knitting of the shorter courses, absorbs considerable power and sets up a frictional heating of the rod and associated parts which requires the circulation of a special cooling medium in many cases. Further, the friction drive is very indefinite in the resultant movement.

The present invention has been devised to eliminate these difficulties associated with the use of friction boxes and for purposes of illustration the preferred formof the present invention has been shown applied to a standard type of straight knitting machine known as the Reade Referring to the somewhat diagrammatic illustrations in Figures 1 and 2, the well known Coulier mechanism indicated in general at A may be briefly referred to as including the small rocker arm I which pivotally supports one end of the pitman arm 2 carrying the spaced rollers 3 which are engaged by the Coulier cam 4 suit- 7 ably driven.

A cross head fitting 5 is mounted on the slidably mounted friction rod 6 and the links I pivotally connected with the cross head fitting 5 are ordinarily connected with the upper end of the main rocker arm, the lower end of which is normally pivoted in a frame bracket at 8.

In the constructions at present in use the main rocker arm comprises a one-piece member so that the full stroke or motion imparted thereto by the draw arm or pitman 2 is transmitted to the cross head fitting 5 and consequently to the friction rod 6 with the result that the friction box 9 slidably mounted on the rod 6 is called upon to absorb all of the excess motion.

According to the present invention the main rocker arm indicated in general at B is formed in relatively displaceable sections I0 and H pivotally connected respectively at the upper and lower ends with the link connections 1 and bracket pivot 8.

The section II is preferably of shorter length than the section Ill and the meeting portions l I and 10 thereof are of disc-like form offset to engage each other in an effective clutch-like or frictional drive manner and if desired a special clutch or frictional facing of suitable frictional characteristics may be inserted between the adjacent faces as indicated at [2,

A clamping bolt I3 is inserted concentrically through the disc-like portions of the arm sections I0 and H to which the end of the pitman arm 2 is pivotally connected and a coil compression spring IA encircles the bolt l3, and in conjunction with the clamping nut I5 any desired degree of frictional resistance may be set up between the disc-like portions Ii) and ii of the respective arm sections.

With this form of drive connection to the friction rod 6 the necessity of permitting relative frictional movement between .the rod 6 and friction box Q is eliminated, and according to the present invention the friction box 9 may be either locked or secured against movement on the rod 6 such as by suitable clamping screws 9 which will be found particularly convenient when applying the present invention to existing machines already equipped with the conventional friction box.

However the present invention makes possible the entire elimination: of the friction box such as shown at 8 in which case a suitable fitting carrying the desired shiftable control connection l6 for selective engagement with the carrier rods Il' may be provided.

The carrier rods il. carry the thread carriers i8 and are adapted to be selectively reciprocatedby the connection it. to. cause the respective yarn carrier iii to directthe thread to the respective loop-forming elements which are supported by the sinker head i9 and the needle bar 2% and which operate in a well known manner.

The carrier rods are normally adapted to engage stopv members 2| positioned at each end of the machine in order to definitely limit the longitudinal travel of the carrier rods and thereby determine the actual length of the course of knit-- ting or of the number of needles in operation.

The stop membersZi are of a well known type and are mountedon an adjustable head 22, one at each end. of the machine, and these heads are in the form of nut. members, each of which engages a shaft member. 23. adapted to be driven at a carefully predetermined rate as determined by the usual narrowing head drive indicated in part at 24.

It will be seen that when the reciprocating carrier rods reach the, end of their reciprocation in either direction as determined by the positioning of the stop members 2|, the rocker arm B formed of the pivotally connected sections ID and II will then have reached its maximum degree of swing without relative pivotal displacement of the sections l0 and II, but as the Coulier motion continues to apply force to the bolt connection l3 the respective portions l0 and H of the arm will then be caused to pivot relatively about the axis of their common pivotal mounting bolt l3 to provide relief for the excess motion at either end of the stroke as indicated particularly in Figure 2.

The frictional value of the disc-like portions !0-ll of the arm sections l0 and Il may be very accurately adjusted so that there will be no excessive friction between the arm sections and there will furthermore be no lost motion at the commencement of the stroke in either direction, since on the return swing of the rocker arm B the motion of the pitman arm 2 will be instantly conveyed to the rod 6 and associated parts.

It will be further appreciated that in absorbing the excess motion in the actual rocker arm B a highly desirable reduction in the rate of travel of the frictional surfaces relative to each other will be achieved as compared to that previously obtaining in connection with the displacement of a friction box on the friction rod.

In the modification shownin Figure 6 the spring element M is in the form of a cupped spring disc having spring fingers held under compression by the nut member if) threaded on the arm connection bolt I3, and the pitman arm 2 is shown independently pivotally connected at 2" to the arm II.

In knitting machines equipped with auxiliary shorter throw arms as indicated at C operated by a pitman arm 25, the arm C may be advantageously constructed in two relatively movable sections as indicated in connection with the arm B as represented by the arm sections 26 and 21, the meet-- ing portions thereof engaging in frictional clutching contact as indicated at 28. under the control of the clamping nut 2s and spring element 38. This arrangement. will eliminate the necessity of. providing a friction box in connection with the arm C in the knitting of toe. or narrower portions of a fabric.

In Figure 7 I have shown a modified form of adjustable stop mechanism adapted to. co-operate with the arms B or C and which may. take the place of the conventional stop. head mechanism 22 including thestops 21.

Referring in detail to Figure '7, the slidable rod 6 is shown provided with. a split sleeve 3| slipped thereon and firmly clamped by the clamping nuts 32 threaded on the tapering end portions. A second pair of clamping nuts 33 are threaded on the enlarged intermediate portion of the sleeve and are adapted to adjustably clamp therebetween a stopmember 34, and in order to provide for micrometer adjustment suitable peripheral markings 35 may be formed on the nuts to cooperate with markings 36 on the stop member.

A rotatable spindle 31, which may represent a standard part of machines at present in use,. or an auxiliary part applied thereto, is here shown provided with left and right-hand threads 38 and 39. Nut members 48 and 41 are threadedly engaged bythe respective threaded portions of the spindle and are non-rotatably guided in a channel 42 or the equivalent. The nut members wand 4| are adapted to form positive stops for engagement with the stop member 34' to limit the length of the stroke of the rod 6 and associated parts as a means of controlling the narrowing or widening of the courses and the spindle 31 is operatively connected with the usual narrowing head control mechanism represented in part at 24, which mechanism is well known and need not be referred to in detail herein.

The present invention may be readily applied at low cost to existing machines or to new machines and in either case will ensure the maximum efli'ciency and dependability, ensuring uniform production of highest quality.

What I claim as my invention is:

1. In a straight knitting machine, the combination with a knitting control member to be reciprocated, of means for reciprocating said member within predetermined limits including relatively rotatable drive members one of which is flexibly connected with said member to be reciprocated at a point spaced from the axis of relative rotation of said respective drive members, and means for controlling the relative rotation of said members in accordance with requirements.

2. In a straight knitting machine, the combination with a knitting control member to be reciprocated, of means for reciprocating said member within predetermined limits including a pair of relatively rotatable members, means forming a floating pivot connection between one of said relatively rotatable members and the member to be reciprocated at a point spaced from the axis of relative rotation of said respective relatively rotatable members, means forming a fixed pivot support for the other of said arms at a point spaced from said axis of relative rotation, and means for frictionally controlling the relative rotation of said members to Prevent such relative rotation until the member to be reciprocated reaches the limit of its stroke.

3. In a straight knitting machine, the combination with a thread-carrier rod, a reciprocable rod, means forming a driving connection between said reciprocable rod and said threadcarrier rod, and means for permitting reciprocation of the said rods within predetermined limits only, of means for imparting reciprocating mot on to said second-mentioned rod including an arm formed in part at least of relatively displaceable sections, means for controllably resisting relative displacement of said sections, one of said sections having a pivotal connection with said second-mentioned rod, and means for displacing said arm as a whole.

4, Means as claimed in claim 3 in which said means forming a driving connection between said respective rods includes a friction box mounted on the second-mentioned rod and means for rigidly securing said friction box thereto against sliding displacement thereon.

5. In a straight knitting machine, the combination with a reciprocable member and a Coulier drive mechanism therefor including a rocker arm formed of sections pivotally connected together and having the Coulier pitman arm connectedthereto adjacent the pivotal connection, one of said arm sections being flexibly connected to said reciprocable member at a point spaced from the axis of the pivotal connection of the arms, and means for frictionally constraining said pivotally connected arm sections against relative rotation until said reciprocable member has been reciprocated a predetermined distance in either direction.

6. In a straight knitting machine, the combination with a reciprocable member and a Coulier drive mechanism therefor including a rocker arm formed of sections pivotally connected together and having the Coulier pitman arm connected thereto adjacent the pivotal connection, and means for frictionally constraining said pivotally connected members against rel-ative rotation until said first-mentioned member has been reciprocated a predetermined distance in either direction, said pivotally connected arm sections being pivotally connected respectively to the frame of the machine and to the reciprocable member, and the Coulier pitman arm being directly connected with the pivot connection of the arm sections.

7. In a straight knitting machine, the comb nation with a reciprocable member and a Coulier drive mechanism therefor including a rocker arm formed of sections pivotally connected together and having the Coulier pitman arm connected thereto adjacent the pivotal connection, and means for frictionally constraining said pivotally connected members against relative rotation until said first-mentioned member has been reciprocated a predetermined distance in either direction, said pivotally connected arm sections being provided with disc-like clutch portions, said frictional constraining means including means for resiliently urging said clutch-like portions into frictional engagement.

FRANCIS MACKAY. 

